Balanced Diet-seminar

A protein which is deficient in one essential amino acid when mixed with another protein having that particular amino acid in sufficient amount, the mixture becomes a superior protein. This is called supplementary value of proteins.

Amino acids may be utilized to synthesize products other than protein or urea. For example:

haem requires glycine

melanin and thyroid hormones require tyrosine

nucleic acid bases require glutamine, aspartate and
glycine

glutathione, which is part of the defence system against
free radicals, requires glutamate, cysteine and glycine.

Nitrogen in the dietary proteins can be estimated, so also the daily urinary nitrogen excretion. If the values are same, the body is said to be in nitrogen balance,.

Positive nitrogen balance is seen in growing children, convalescent patients, pregnancy, etc. On the other hand, negative nitrogen balance is seen in glucorticoid excess, thyrotoxicosis, etc., and above all, in the cases of protein malnutrition (less protein in diet).